Power-transmission gearing



G. E. CASSEL.

PowER TRANSMISSION GEAHING.

APPLICATION FILED NOV. 4. i919.

Panted Mar. 2,1920.

UNITED sTATEs `PATENT oEEioE.

GUNNAE ELIAS CASSEL, or DJURSHOLM, SWEDEN, ASSIGNoE To AKTIEBOLAGET Grito,

l 0E STOCKHOLM, SWEDEN.

ZPOWERfTRANSMISSION GEARING.

Specification of Letters Patent.

Patented Mar.2,192o.

Applicationled November 4, 1919. l Serial No. 335,769.

.-it has been proposed, in order to obtain a great ratio of gearing by means of a cornpact and reliable gearing to use a gearing comprising a gyratorically swinging thrust disk mounted on one of the shafts and having a pluralitj7 of radial projections, a-casing or drum surrounding the'thrust-disk and having an endless cam slot engaged by theJ said projections, and a guide-way causving the disk to move in an axial plane one of the said last-mentioned elements, viz. the

drum or the casing, being secured to the other shaft, while the other of said elements is mounted stationary.

Whenthe thrust-disk is thus caused to move in an axial plane, it has been found that different points of the disk will follow different paths in the movement of the disk so that not more than two rojections of the disk-provided they are iametrically opposite--may engage the same endless slot of the, drum. To suitably distribute the power output of the disk it is, however, necessary to provide more than twol projections so that two separate slots at least must be formed on the drum. As said slots will not be completely independent of each other but will partly coincide the slots must be.

situated at different radial distances from the center of the disk thereby rendering the making of the slots diiicult and giving but comparatively small contact surfaces in each slot.

In order to overcome said difficulties, the

guide-way is formed, according to this invention, in such a way that all points of the disk will describe e ual paths in the movement of the thrust-disk. This will result inthat a plurality of projections of the thrustdisk may engage one and the'same slot of the drum, moreover, it will be possible to use a plurality of equal guide-ways for the drum, preferably uniformly distributed around the drum so that the load' on the thrust-disk will be uniformly distributed to the greatest extent possible.

` In the accompanying drawing, one embodiment of the invention is illustrated.v

Figure lshows a, longitudinal section, and F1g.2 showsacross section of a gearing embodying this invention, while Fig. 3 shows adetail.

l/Vith reference to the drawing, the numerals 1 and 2 indicate two shafts lying in the alinement of one another and being eX- actly -centered with respect to each other. The -E shaft 1' carries an obliquely arranged .disk-shaped driving member 3 keyed to the with disk-shaped heads 8, engaging an endless cam slot 9 formed in the inner surface of a stationary drum surroundin the disk The end walls of said drum orm bearings foI the ends of the shafts 1 and 2.

Formed between the projections 7 are projections 11 carrying antifriction rollers 12 each engaging a separate guide-way formed by a slot 14 in an arm 13 rigidly secured to the shaft 2. The guide-arms 13 extend aXially, the slots 14 thereof being, however, not straight inasmuch as the fundamental form of the slot consists of an eight, as indicated by dotted lines in Fig. 3, which shows a guiding arm 13 seen from the shaft. The said form of the slot'14 is so chosen that all points of the thrust-disk will describe equal paths in the movement of the thrust-disk. Owing thereto, a plurality of projections of the thrust-disk may engage one and the same slot of the drum, the number of such projections depending only on the number of waves of the slots. Furthermore, any desired number of projections 11 and guiding arms 13 may be provided so as to obtain a uniform loading of the thrust-disk when in operation.

Assuming the shaft 1 is the driving Shaft, the disk 4 will upon the rotation of the shaft 1 be caused to perform a swinging movement corresponding to a wave-movement proceeding along the periphery of the disk. Due to the engagement of the projections 7, 8 with the stationary cam-slot 9, the disk 4 is caused to perform a circumferential movement the number of waves of the slot 9 determining the ratiol of gearing inasmuch as each projection 7 8 will at each revolution of the shaft 1 pass through one wave of the slot 9. Owing to the lengagement of the projections 11 with the guiding arms 13, the shaft 2 will be caused to follow the disk in its peripheral movement but while the thrust disk does not move with a uniform speed, the shaft 2 due to the special form of r lthe guiding slots 14 will be rotated continuously. j

The form of the guiding slots 14 above described may be obtained either experimentally lor mathematically. The method of obtaining said form forming no part of this invention will not be described herein.

What I claim is :f-

l. A power transmission gearing for shafts being in alinement with one another, comprising an oblique disk, attached to one of-said shafts, a thrust-.disk loosely mounted on said oblique disk and performing a gyratoric swinging'movement during the rota tion ofy said shaft, a drum inclosing thev thrust disk and having an endless cam slot, radial projections on said thrust-disk engaging in said slot, .guide-ways, other radial projections on `said thrust-disk engaging in said guide-ways, said guide-ways and said casingbeing adapted to perform a rotation with relation to each other during the gyratoric movement of the thrust-disk, the said guide-ways having such shape that all points of the thrust-disk will describe equal paths during said movement.

2. A power transmission gearing, comprising a rotary shaft, an'oblique disk attached to said shaft, another disk loosely mounted on said oblique disk, radial projections on said thrust-disk, a stationary casing inclosing the thrust-disk, and having an endless cam slot on its inner surface, engaged by some of said projections, another shaft, lying in alinement to the said firstmentioned shaft, arms attached to said other shaft and having guiding slots formed therein engaged by projections of said thrust-disk, ythe shape of said slots being such as to cause all points of the thrust-disk during the rotation of said first-mentioned shaft to perform movements in equal paths.

In testimony whereof I have signed my name. GUNNAR ELIAS CASSEL. 

